What are your arguments?LCSphysicist said:Homework Statement:: A radially pulsating charged sphere
(a) emits electromagnetic radiation
(b) creates a static magnetic field
(c) can set a nearby electrified particle into motion.
Relevant Equations:: .
I know that (a) is right, and (b) is wrong. The problem is with (c)... It seems correct to me! I can't see how this is not true. The electric charge o the sphere by itself will create an electric field, which will move the particle.
"The electric charge of the sphere by itself will create an electric field, which will move the particle." is my argument.Orodruin said:What are your arguments?
I meant for all of the problems.LCSphysicist said:"The electric charge of the sphere by itself will create an electric field, which will move the particle." is my argument.
(a) is correct. It emit radiation, obviously: Since the electric field configuration outside the sphere need to be oscillating, the information arriving at this point comes from the radiation that the oscillation of the sphere produces.Orodruin said:I meant for all of the problems.
Here is a hint: there is no electromagnetic monopole radiation.LCSphysicist said:(a) is correct. It emit radiation, obviously: Since the electric field configuration outside the sphere need to be oscillating, the information arriving at this point comes from the radiation that the oscillation of the sphere produces.
Now, i know there is a physical meaning for radiation, which is the term that didn't goes to zero at r infinity. If this is what the question is asking, that is, if this term is present on the potential, i can't say.
I can think about it late, but thank you. By now, i would like to understand how can "c" be wrong.Orodruin said:Here is a hint: there is no electromagnetic monopole radiation.
OOp, right in time XD.hutchphd said:Why do you think it wrong ?
LCSphysicist said:OOp, right in time XD.
Because the answer provided is only a.
I don't know it it will help you @LCSphysicist , but think about how an antenna works. You drive a voltage differentially between the two antenna elements to create a differential voltage and current, and that's what creates the EM field that propagates away from the antenna. If you drive the two antenna elements with the same common-mode current, there is no differential current, so no launching of the EM waveform.Orodruin said:Here is a hint: there is no electromagnetic monopole radiation.
What is the field outside a uniformly charged spherical shell of radius r?LCSphysicist said:Since the electric field configuration outside the sphere need to be oscillating
Well, that is wrong, so …LCSphysicist said:OOp, right in time XD.
Because the answer provided is only a.
A radially pulsating charged sphere creates electromagnetic radiation by accelerating the charged particles within it. As the particles move back and forth, they create changing electric and magnetic fields, which then propagate outward as electromagnetic waves.
The frequency of the emitted radiation is equal to the frequency of pulsation of the charged sphere. This is because the frequency of the emitted radiation is directly determined by the frequency of the oscillating charged particles.
Yes, a radially pulsating charged sphere can emit a range of electromagnetic radiation, including radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays. The specific type of radiation emitted depends on the frequency of pulsation and the energy of the charged particles.
The amplitude of pulsation directly affects the intensity of the emitted radiation. A larger amplitude of pulsation results in a higher intensity of radiation, while a smaller amplitude results in a lower intensity. This is because a larger amplitude means the charged particles are moving with a greater distance and speed, creating stronger electric and magnetic fields and thus more intense radiation.
No, a radially pulsating charged sphere can only emit radiation while it is pulsating. When the pulsation stops, the acceleration of the charged particles also stops, and thus no electromagnetic radiation is produced. However, the emitted radiation may continue to propagate outward for some time after the pulsation has ceased.